This invention relates to thumbnuts and/or wingnuts and their specific use.
In the past various attempts have been made to provide thumbnuts for use with articles of manufacture during the assembly thereof, particularly in the case of consumer assembly where the criteria for assembly should be ease and quickness in which the use of tools is kept to a minimum. One example of such an article of manufacture is a hand cart or wheelbarrow disclosed in U.S. Pat. Nos. 4,991,716 and 4,889,360 assigned to the present assignee, in which the consumer is invited to assemble the product without the need of any tools whatsoever. In such cases the various thumbnuts or wingnuts provided with the product and used to secure the various parts of the product together have to be sufficiently tightened in order for the product to operate in a safe manner. In such cases, recourse to a tool, such as a wrench and the like, is sometimes necessary to insure that the nuts are tightened, especially if the consumer lacks sufficient manual strength to tighten the nuts in a workman-like manner.
There is a need, therefore, to provide thumbnuts or wingnuts which can be tightened sufficiently by anyone, regardless of their individual strengths, in order to implement the assembly of a product, such as described above, in which a tubular member is secured to another member and in which the thumbnuts so provided are caused to be secured in a simple and an easily tightenable manner without fear of the nuts being subsequently loosened during normal use of the product.